JP2004358471A

JP2004358471A - Device for fastening automatic drilling rivet

Info

Publication number: JP2004358471A
Application number: JP2001395691A
Authority: JP
Inventors: Choji Naito; 暢治内藤; Shuichiro Iwatsuki; 修一郎岩月; Masa Fujita; 雅藤田
Original assignee: Honda Motor Co Ltd; Nippon Pop Rivets and Fasteners Ltd
Current assignee: Honda Motor Co Ltd; Nippon Pop Rivets and Fasteners Ltd
Priority date: 2001-12-27
Filing date: 2001-12-27
Publication date: 2004-12-24
Anticipated expiration: 2021-12-27
Also published as: JP4097428B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for fastening an automatic drilling rivet which reduces or eliminates restrictions in the driving direction of a member to be fastened. <P>SOLUTION: The device for fastening the automatic drilling rivet is composed as follows. A die 18 of the device for fastening the automatic drilling rivet is composed of a center pin 25, which receives the hollow part of a leg part 5 of the automatic drilling rivet 1, and a die body 27 in which a recessed part 26 for guiding the radially outward deformation of the tip at the leg part of the automatic drilling rivet is formed on the outer peripheral side of the center pin 25. The center pin 25 and the die body 27 are relatively movably supported along in the axial direction of the center pin 25. which goes toward a punch 14. When the automatic drilling rivet 1 pressed by the punch 14 is driven into the members 2, 3 to be fastened and its tip at the leg part starts to drill through the member 3 to be fastened on the receiving side, a disc spring 41 relatively moves the center pin 25 to the die body 27 so that the center pin 25 is brought into contact with the face on the die side of the member 3 to be fastened on the receiving side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【産業上の利用分野】
本発明は、大径の頭部と該頭部から垂下する中空の脚部とを有する自動穿孔リベットを複数の被締結部材に締結する自動穿孔リベット締結装置に関し、特に、自動車組立て等の板金組立作業（特にアルミニウムボデーの組立作業）で、２枚若しくは３枚以上の板部材（又は板部材と部品）である被締結部材を自動穿孔リベットを使用して相互に締結する自動穿孔リベット締結装置に関する。
【０００２】
【従来の技術】
自動穿孔リベット締結装置の１例が、特表平８−５０５０８７号公報に記載されている。その図１には、自動穿孔リベットの１例が示されている。自動穿孔リベットは、大径の頭部と該頭部から垂下する中空の脚部とを有し、締結装置のパンチとダイによって、例えば２枚のボデーパネルである被締結部材に打ち込まれると、脚部はパネルを穿通しつつ脚部の先端が拡がるように変形し、この変形拡開脚部と大径の頭部とによって両被締結部材が相互に連結される。自動穿孔リベットは、溶接に不向きなアルミニウムボデーパネルの連結に適しており、現在軽量化が進められている自動車のボデーではアルミニウムボデーが採用され、自動穿孔リベットの需要は増大している。特に、自動穿孔リベットは、パンチ側の被締結部材は穿通するが、ダイに隣接する受側の被締結部材を貫通せずにその中に留まるように打込まれるので、これによって、受側の被締結部材の表面にはリベット穿通穴が形成されない。そのため、受側の被締結部材への密封性が損なわれず、また外観がそのまま維持される利点がある。
【０００３】
現在の自動穿孔リベットの打込みでは、パンチからの打込方向においてパンチ側の被締結部材の厚さが、ダイに隣接する受側の被締結部材より厚い場合、リベット脚部が受側被締結部材に斜めに穿通してできる半径方向の穿通長さすなわちアンダーカット量が少なく、十分な結合強度が得られないことがあった。その様子を図１に示す。図１は、自動穿孔リベット１が、２枚の被締結部材２及び３に打込まれて、パンチ側の被締結部材２（図示の例では１枚であるが複数枚あってもよい）とダイに隣接する受側の被締結部材３を締結する様子を示している。自動穿孔リベット１は、大径の頭部４と該頭部から垂下する中空の脚部５とを有する。図示のように、パンチ側の被締結部材２が受側被締結部材３より厚い場合、自動穿孔リベットの脚部５が受側被締結部材３に斜めに穿通してできる半径方向穿通長さすなわちアンダーカット量６が少なくなってしまい、被締結部材３を被締結部材２に結合するのに十分な強度が得られない。現在、パンチ側の被締結部材の厚さとダイに隣接する受側被締結部材の厚さの比率は、十分な結合力を得るためには、２：１を越えられないとされている。
【０００４】
【発明が解決しようとする課題】
上記のような制約があるため、自動穿孔リベットの打込部位には、受側被締結部材が、それ以外の被締結部材の厚さの１／２以下の薄いものにならないようにするため、打込み方向の制約がある。例えば、図１において、被締結部材２の厚さが他の被締結部材３の厚さに対して、例えば、３：１とか４：１等のように、２：１を越えてしまう場合、受側被締結部材を被締結部材３として自動穿孔リベットを打込むと、図示のように、十分なアンダーカット量が得られず、そのため十分な締結強度が得られない。そこで、リベット締結装置を反転させて、被締結部材２を受側被締結部材としたり、被締結部材２及び被締結部材３を全体的に反転させて、同じように被締結部材２を受側被締結部材として、被締結部材２と３を十分な強度で締結するようにしている。しかし、締結装置の反転や被締結部材の反転には時間を必要とし、締結作業を迅速に行うことができなかった。また、被締結部材の形状の制約や、締結部位の制約等によっては、上記の反転ができない場合があった。
【０００５】
国際公開番号ＷＯ００／２３２１３号公報には、ダイを、締結装置本体に固定したダイ本体と、ダイ本体の中に軸方向に移動可能に支持した中央ピンとで構成し、ダイ本体には自動穿孔リベットの脚部先端の半径方向外方への変形をガイドする凹部が形成されている、自動穿孔リベット締結装置が開示されている。この締結装置では、自動穿孔リベットを被締結部材の打込む最初のときにおいて、自動穿孔リベットの脚部の中央を位置決めするため、中央ピンが突出して被締結部材に当接させられ、リベットの打込みの最終工程においては中央ピンはダイ本体に引込まれている。この従来の自動穿孔リベット締結装置は、自動穿孔リベットの打込みのときの中心の位置決めを行うものであって、被締結部材へのアンダーカット量の不足に伴う不十分な締結を解消するものではない。
【０００６】
従って、本発明の目的は、被締結部材の打込方向の制約を減少し又は解消する自動穿孔リベット締結装置を提供するにある。
【０００７】
【課題を解決するための手段】
かかる目的を達成するため、本発明は、大径の頭部と該頭部から垂下する中空の脚部とを有する自動穿孔リベットを複数の被締結部材に打込むパンチとダイを有し、前記自動穿孔リベットを前記被締結部材に打込むと、前記脚部が被締結部材を穿通しつつ脚部先端が半径方向外方に拡がるように変形させられ且つ該脚部先端は前記ダイに隣接する受側の被締結部材を貫通せずにその中に留まるように打込まれ、前記変形拡開脚部と前記頭部とによって前記複数の被締結部材を相互に連結する、自動穿孔リベット締結装置であって、前記ダイは、前記自動穿孔リベットの脚部の中空部分を受ける位置にあって前記パンチに向けて延びる中央ピンと、該中央ピンの外周側に、前記自動穿孔リベットの脚部先端の半径方向外方への変形をガイドする凹部が形成されたダイ本体とから成り、前記中央ピンと前記ダイ本体とは、前記パンチに向う中央ピンの軸方向に沿って相対的に移動可能に支持されており、前記パンチによって押圧された自動穿孔リベットが前記被締結部材に打込まれてその脚部先端が前記受側の被締結部材を穿通し始めるとき、前記中央ピンが該受側被締結部材のダイ側の面に当接するように、該中央ピンを前記ダイ本体に対して相対的に移動させる手段を有することを特徴とする自動穿孔リベット締結装置を提供する。
【０００８】
かかる自動穿孔リベット締結装置によれば、ダイの中央ピンが、自動穿孔リベットの脚部先端がダイに隣接する受側の被締結部材を穿通し始めるとき、その受側被締結部材のダイ側の面に当接し、それ以前まで中央ピンは受側の被締結部材には作用しないので、自動穿孔リベット脚部は受側の被締結部材に進入するまでは拡開することなく直進し、リベット脚部が受側被締結部材に穿通し始めると、中央ピンが突き上がって、リベット脚部の先端を半径方向外方に大きく展開させて拡開させ始め、その展開の大きさによって、十分なアンダーカット量が得られる。この十分なアンダーカット量によって、受側の被締結部材の厚さが他の被締結部材（すなわちパンチ側の被締結部材）の厚さの１／２以下の薄いものであっても、十分な結合力を得ることができる。そのため、被締結部材の打込方向の制約を減少し又は解消することができ、従来の締結装置のように、締結装置を反転させたり、被締結部材を反転させる手間を減少させ、又は省くことができ、迅速な締結が可能になる。そして、従来の締結不能な打込方向であっても締結が可能になり、締結部位の制約が解消されて、自動穿孔リベットの適用個所又は部位が拡大する。
【０００９】
上記の自動穿孔リベットにおいて、Ｃ型フレームを備え、パンチは、Ｃ型フレームの一端に、該Ｃ型フレームに他端に向けて移動可能に取付けられ、ダイは、Ｃ型フレームの他端に、パンチによって打込まれる自動穿孔リベットを受けるように該パンチに対向して取付けられ、ダイ本体は、Ｃ型フレームの前記他端に、中央ピンの軸方向に移動可能に支持されており、中央ピンは、Ｃ型フレームの前記他端にダイ本体を貫通しピンの先端がパンチに向けて突出するように固着されており、中央ピンをダイ本体に対して相対的に移動させる手段は、ダイ本体とＣ型フレームの間に設けられてダイ本体をパンチ側に付勢するばね手段にできる。
【００１０】
その場合、可動のダイ本体は、パンチ側の大径の筒状部分と、Ｃ型フレームの前記他端の取付穴の中をスライドする小径の筒状部分とから成り、両筒状部分の中心には中央ピンをスライド可能に受け入れる穴が貫通している、中空の筒状体として形成されており、ばね手段は、大径筒状部分とＣ型フレームとの間に設けられた皿ばねで成り、該皿ばねの付勢力は、パンチによって打込まれた自動穿孔リベットの脚部先端が被締結部材を穿通して受側の被締結部材に進入するときまでは、可動のダイ本体をパンチ側に付勢するが、パンチによって自動穿孔リベット脚部を受側被締結部材に穿通し始める強い押圧力が加わるとダイ本体がＣ型フレーム側へ移動して、中央ピンが該受側被締結部材のダイ側の面に当接するのを可能にするばね力である。
【００１１】
更に、Ｃ型フレームの前記他端には、ダイ本体の小径筒状部分をスライド可能に収容する取付穴が形成されており、該Ｃ型フレームの他端には、更に、パンチと反対側において取付穴に続く大径の中央ピン収容穴が形成されており、取付穴には、ダイ本体が、小径筒状部分においてスライド可能に取付けられており、中央ピン収容穴には内壁に雌ねじが形成されており、該中央ピン収容穴には、中央ピンが雌ねじへの螺合によって取付けることができる。
【００１２】
また、上記のＣ型フレームを有する自動穿孔リベットにおいて、Ｃ型フレームを備え、ダイ本体は、Ｃ型フレームの前記他端に固着され、該ダイ本体には、中央ピンを、該ピンの先端がダイ本体を貫通しパンチに向けて突出するように収容する中央ピン収容室が形成され、中央ピンは、中央ピン収容室の中に該ピンの軸方向に沿って移動可能に支持されており、中央ピンをダイ本体に対して相対的に移動させる手段は、油圧又は空圧によって中央ピンをパンチ側に付勢する油圧又は空圧手段であってもよい。その場合、油圧又は空圧手段は、パンチによって打込まれた自動穿孔リベットの脚部先端が被締結部材を穿通して受側の被締結部材に進入するときまでは、中央ピンを移動させないが、パンチによって自動穿孔リベット脚部を受側被締結部材に穿通し始める強い押圧力が加わると、中央ピンを受側被締結部材のダイ側の面に当接させるように動作するようにする。
【００１３】
【発明の実施の形態】
以下、図面を参照して、本発明の実施例を説明する。図２は、本発明の１実施例に係る自動穿孔リベット締結装置９の全体の概略を示している。図２において、自動穿孔リベット締結装置９は、多関節型ロボットアーム（図示せず）への連結部１０が設けられたＣ型フレーム１１を有する。Ｃ型フレーム１１は、上部の水平アーム部分と連結部１０が取付けられた垂直アーム部分と下部の水平アーム部分とが一体になった剛体で成る。Ｃ型フレーム１１の上部水平アーム部分の端部すなわち一端の側には、自動穿孔リベット締結装置の主部分となる締結機構部１３が取付けられている。締結機構部１３には、先端（図２において下端）の側にパンチ１４が移動可能に取付けられて、パンチ１４から更に先端側にレシーバ部１５が設けられている。レシーバ部１５に送られてそこに保持された自動穿孔リベット（例えば図１の自動穿孔リベット１を参照されたい）は、パンチ１４によって打込まれる。パンチ１４の上方にはスピンドル駆動部１７が設けられ、パンチ１４を押込んで、その下側のレシーバ部に保持された自動穿孔リベットを打込む。ダイ１８が、Ｃ型フレーム１１の下部水平アームの端部すなわちＣ型フレームの他端に取付けられている。スピンドル駆動部１７は、例えば、駆動用電動モータ１９とモータの回転力を伝達する減速歯車機構２１及び歯車機構２２と、モータからの回転力によって回転しつつ上下動するリードスクリュー２３とを備え、電動モータの回転によって、リードスクリューが下動し、この運動がパンチ１４に伝達されてレシーバ部１５に保持した自動穿孔リベットを強力にダイ１８の側に押し込む。複数の被締結部材（例えば、図１の被締結部材２及び３を参照されたい）は、ダイ１８の上に載置され、パンチ１４の下降によって複数の被締結部材に自動穿孔リベットが穿孔しつつ挿入されてそれらの被締結部材は相互に締結される。
【００１４】
Ｃ型フレーム１１の他端に自動穿孔リベットを受けるように取付けられた、本発明に係るダイ１８の詳細が図３に示されている。図３において、ダイ１８は、自動穿孔リベットの脚部の中空部分、更に詳細にはリベット脚部の軸心位置を受ける位置にあって且つパンチに向けて延びる中央ピン２５と、中央ピン２５の外周の回りに自動穿孔リベットの脚部先端が半径方向外方へ変形するのをガイドする凹部２６が形成されたダイ本体２７とから成る。中央ピン２５とダイ本体２７とは、Ｃ型フレーム１１の他端部分に、パンチ１４に向う中央ピン２５の軸方向に沿って相対的に移動可能に支持されている。この実施例においては、ダイ本体２７は、Ｃ型フレーム１１に、中央ピン２５の軸方向に移動可能に支持されており、中央ピン２５は、Ｃ型フレーム１１に固着されてダイ本体２７を貫通しピンの先端がパンチ１４に向けて突出する。そのため、可動のダイ本体２７は、パンチ側の大径の筒状部分３０と、Ｃ型フレーム１１に形成された取付穴３１の中をスライドする小径の筒状部分３３とから成り、両筒状部分の中心には、中央ピン２５をスライド可能に受け入れる穴３４が貫通した中空の筒状体として形成されている。Ｃ型フレーム１１には、更に、ダイ本体２７の取付穴３１の下方に大径の中央ピン収容穴３５が形成され、中央ピン収容穴３５には内壁に雌ねじが形成されている。中央ピン２５には、大径の円筒状取付部３８が形成されてその外周面に、中央ピン収容穴３５の雌ねじに適合する雄ねじが形成されている。これによって、中央ピン収容穴３５に中央ピン２５の取付部３８をねじ込んで中央ピン２５をＣ型フレーム１１に固着できる。なお、中央ピン２５の固着が緩まないように、止めねじ３９がＣ型フレーム１１に取付けられる。
【００１５】
本発明において、パンチ１４によって押圧された自動穿孔リベットが被締結部材に打込まれてその脚部先端が受側の被締結部材（図１の被締結部材３を参照されたい）を穿通し始めるとき、中央ピン２５が受側被締結部材のダイ側の面に当接するように、中央ピン２５をダイ本体２７に対して相対的に移動させる手段が設けられている。図３に示す実施例において、ダイ本体２７とＣ型フレーム１１の間に設けられてダイ本体２７をパンチ１４の側に付勢するばね手段である。具体的には、ばね手段は、大径筒状部分３０とＣ型フレーム１１との間に設けられた皿ばね４１で成る。皿ばね４１は、Ｃ型フレーム１１に置かれた座４０の上に載置され、皿ばね４１が撓んだときのＣ型フレームの摩耗を防止している。皿ばね４１の付勢力すなわち大径筒状部分３０をパンチ側に押上げる力は、パンチによって打込まれた自動穿孔リベットの脚部先端が被締結部材を穿通して受側の被締結部材に進入するときまでは、可動のダイ本体をパンチ側に付勢するが、パンチによって自動穿孔リベット脚部を受側被締結部材に穿通し始める強い押圧力が加わるとき、ダイ本体２７がＣ型フレーム１１の側へ移動して、中央ピン２５が受側被締結部材のダイ側の面に当接するのを可能にするばね力に設定されている。なお、小径筒状部分３３の下端には、前記皿ばねの付勢力によって取付穴３１からダイ本体２７が抜け出ないようにするため、止め用のＣリング４２が設けられている。
【００１６】
かかる自動穿孔リベット締結装置９を用いて自動穿孔リベットを打込む動作を図４及び図５を参照して説明する。図４において、自動穿孔リベット１は、給送部（図示せず）からレシーバ部１５に自動給送されて、レシーバ部１５の中でパンチ１４の下方にあるように保持される。パンチ１４は、スピンドル駆動部１７（図２）からの押込み力を受けて、下方に下がって自動穿孔リベット１を、パンチ側の被締結部材２に打込む。この打込みによって自動穿孔リベット１の中空の脚部５が被締結部材２を穿通して進む。図４に図示のように、本発明において、打込みの第１段階では、ダイ１８のダイ本体２７はせり上がった状態にあり、中央ピン２５はダイ１８に隣接する受側の被締結部材３には当接しないので、自動穿孔リベット脚部５は被締結部材２の中を拡開することなく直進する。その後、自動穿孔リベット脚部５の穿通が進んでダイに隣接する受側の被締結部材３に至り、パンチ１４からのリベットへの押圧力がその受側の被締結部材３をリベット脚部５が穿通する程の強い力になると、皿ばね４１が撓んで、ダイ本体２７がＣ型フレーム１１の側に下がる。その様子が図５に示されている。
【００１７】
図５において、自動穿孔リベット１の脚部５の先端がダイ１８に隣接する受側の被締結部材３を穿通し始めるとき、中央ピン２５の先端が受側被締結部材３のダイ側の面に当接するようになる。中央ピン２５は、パンチ１４の押圧力を受ける受側被締結部材の押圧力に対抗して、当接位置の受側被締結部材３の部分を突き上げるように作用し、その位置がリベット脚部５の中心位置にあるので、自動穿孔リベット１のリベット脚部５の先端を半径方向外方に大きく展開させて拡開させ始める。これによって、脚部５は半径方向外方に大きく拡開するように変形して受側被締結部材の中を穿通し、受側被締結部材を貫通する手前で打込みは終了するが、脚部５は半径方向への変形量が大きく、脚部５の半径方向の穿通長さすなわちアンダーカット量が十分に得られる。２枚の被締結部材２及び３は、自動穿孔リベット１の変形拡開脚部５と大径頭部４とによって相互に締結される。本発明においては、拡開した脚部５の十分なアンダーカット量によって、受側の被締結部材３の厚さが他の被締結部材２（すなわちパンチ側の被締結部材）の厚さの１／２以下の薄いものであっても、被締結部材２と３とは十分な結合力で相互に締結させることができる。それによって、被締結部材の打込方向の制約を減少し又は解消することができ、従来の自動穿孔リベット締結装置のように、締結装置を反転させたり、被締結部材を反転させる手間を減少させ、又は省くことができ、迅速な締結が可能になる。そして、従来の締結不能な打込方向であっても締結が可能になり、締結部位の制約が解消されて、自動穿孔リベットの適用個所又は部位が拡大する。
【００１８】
図６は、本発明に係る自動穿孔リベット締結装置の他の実施例を示しており、この実施例では、ダイ４３は、Ｃ型フレーム１１に、パンチ１４に対向して固着されたダイ本体４５と、ダイ本体４５の中に移動可能に保持された中央ピン４６とから成る。そのため、ダイ本体４５には、中央ピン４６をピンの先端がダイ本体を貫通してパンチ１４に向けて突出するように収容する中央ピン収容室４７が形成されている。中央ピン４６は、中央ピン収容室４７の中にピンの軸方向に沿って移動可能に支持されている。従って、この実施例では、中央ピン４６がパンチ１４の側に移動する。その移動のための手段は、ポンプ４９等の油圧又は空圧を中央ピン収容室４７の下部から供給して中央ピン４６をパンチ側に付勢する、油圧又は空圧手段である。この油圧又は空圧手段は、パンチ１４によって打込まれた自動穿孔リベットの脚部先端５がパンチ側の被締結部材２を穿通して受側の被締結部材３に進入するときまでは、中央ピン４６を移動させないが、パンチ１４によって自動穿孔リベット脚部５を受側被締結部材３に穿通し始める強い押圧力が加わると、中央ピン４６を受側被締結部材３のダイ側の面に当接させるように動作する。図６のダイ４３を用いた場合も図４及び図５において説明したのと同様に、自動穿孔リベット１を被締結部材２及び３に打込んだ場合、自動穿孔リベット１の脚部５は十分なアンダーカット量で受側被締結部材３に穿通する。
【００１９】
【発明の効果】
本発明によれば、ダイの中央ピンは、自動穿孔リベットの脚部先端がダイに隣接する受側被締結部材を穿通し始めるときまでは受側被締結部材には作用せず、リベット脚部先端が受側被締結部材を穿通し始めると中央ピンが確実に作用するので、受側被締結部材に進入するまでは拡開することなく直進していたリベット脚部が受側被締結部材に穿通し始めると、中央ピンが作用してリベット脚部の先端を半径方向外方に大きく展開させて拡開させ始め、十分なアンダーカット量が得られる。この十分なアンダーカット量によって、受側の被締結部材の厚さが他の被締結部材（すなわちパンチ側の被締結部材）の厚さの１／２以下の薄いものであっても、十分な結合力を得ることができ、被締結部材の打込方向の制約を減少し又は解消することができ、従来の締結装置のように、締結装置を反転させたり、被締結部材を反転させる手間を減少させ、又は省くことができ、迅速な締結が可能になる。更に、従来の締結不能な打込方向であっても締結が可能になり、締結部位の制約が解消され、自動穿孔リベットの適用個所や部位が拡大する。
【図面の簡単な説明】
【図１】自動穿孔リベットが従来の締結装置によって打込まれた被締結部材の締結の様子を示す断面図である。
【図２】本発明の１実施例に係る自動穿孔リベット締結装置の概略正面図である。
【図３】本発明の１実施例に係る自動穿孔リベット締結装置のダイ部分の断面図である。
【図４】図２及び図３に示す自動穿孔リベット締結装置を用いて被締結部材に自動穿孔リベットを打込む途中の状態を示す、ダイ及びパンチ部分の断面図である。
【図５】本発明に係る締結装置を用いて自動穿孔リベットを被締結部材に打込んで被締結部材を相互に結合した状態を示す、図４と同様の断面図である。
【図６】本発明の他の実施例に係る自動穿孔リベット締結装置のダイ部分の断面図である。
【符号の説明】
１自動穿孔リベット
２パンチ側の被締結部材
３受側被締結部材
４自動穿孔リベットの大径頭部
５自動穿孔リベットの脚部
６アンダーカット量
９自動穿孔リベット締結装置
１０ロボットアームへの連結部
１１Ｃ型フレーム
１３締結機構部
１４パンチ
１５レシーバ部
１７スピンドル駆動部
１８ダイ
１９モータ
２１減速歯車機構
２２歯車機構
２３リードスクリュー
２５中央ピン
２６ガイド用の凹部
２７ダイ本体
３０大径筒状部分
３１取付穴
３３小径筒状部分
３５中央ピン収容穴
３７雌ねじ
３８中央ピンの取付部
３９止めねじ
４１皿ばね
４２Ｃリング
４３ダイ
４５ダイ本体
４６中央ピン
４７中央ピン収容室
４９ポンプ[0001]
[Industrial applications]
The present invention relates to an automatic piercing rivet fastening device for fastening an automatic piercing rivet having a large-diameter head and a hollow leg hanging down from the head to a plurality of members to be fastened, and in particular, to a sheet metal assembly such as an automobile assembly. The present invention relates to an automatic piercing rivet fastening device for mutually fastening two or three or more plate members (or a plate member and parts) to each other using an automatic piercing rivet in an operation (particularly, an assembly operation of an aluminum body). .
[0002]
[Prior art]
One example of an automatic piercing rivet setting device is described in JP-T-8-505087. FIG. 1 shows an example of an automatic drilling rivet. The self-piercing rivet has a large-diameter head and a hollow leg hanging from the head, and is driven by a punch and a die of a fastening device into a member to be fastened, for example, two body panels. The leg is deformed so that the tip of the leg is expanded while penetrating the panel, and the members to be fastened are connected to each other by the deformed expanded leg and the large-diameter head. The self-piercing rivet is suitable for connecting an aluminum body panel that is not suitable for welding, and the body of an automobile whose weight is being reduced is adopting the aluminum body, and the demand for the self-piercing rivet is increasing. In particular, since the self-piercing rivet penetrates the member to be fastened on the punch side, it is driven so as not to penetrate the member to be fastened on the receiving side adjacent to the die but stays therein, so that No rivet penetration hole is formed in the surface of the member to be fastened. Therefore, there is an advantage that the sealability of the receiving side to the member to be fastened is not impaired and the appearance is maintained as it is.
[0003]
In the current driving of the automatic piercing rivet, when the thickness of the member to be fastened on the punch side in the driving direction from the punch is thicker than that of the member to be fastened on the receiving side adjacent to the die, the rivet legs are connected to the member to be fastened on the receiving side. In this case, the penetration length in the radial direction, that is, the amount of undercut, which is formed by oblique penetration, is small, and sufficient bonding strength may not be obtained. This is shown in FIG. FIG. 1 shows that an automatic piercing rivet 1 is driven into two members to be fastened 2 and 3, and that a punch-side member to be fastened 2 (one piece in the illustrated example, but there may be a plurality of pieces). Fig. 3 shows a state in which a receiving-side fastened member 3 adjacent to a die is fastened. The self-piercing rivet 1 has a large diameter head 4 and a hollow leg 5 hanging from the head. As shown in the drawing, when the punch-side fastened member 2 is thicker than the receiving fastened member 3, the radial piercing length of the self-piercing rivet leg 5 formed by obliquely penetrating the receiving fastened member 3, that is, The undercut amount 6 is reduced, so that sufficient strength cannot be obtained for coupling the member 3 to be fastened to the member 2 to be fastened. At present, the ratio of the thickness of the member to be fastened on the punch side to the thickness of the member to be fastened on the receiving side adjacent to the die cannot exceed 2: 1 in order to obtain a sufficient bonding force.
[0004]
[Problems to be solved by the invention]
Due to the above-described restrictions, the receiving part to be fastened to the part where the automatic piercing rivet is to be driven is not to be as thin as 1/2 or less of the thickness of the other to-be-fastened members. There are restrictions on the driving direction. For example, in FIG. 1, when the thickness of the member to be fastened 2 exceeds 2: 1 with respect to the thickness of the other members to be fastened 3 such as 3: 1 or 4: 1, for example, When an automatic piercing rivet is driven with the receiving member to be fastened as the fastened member 3, as shown in the figure, a sufficient amount of undercut is not obtained, and thus a sufficient fastening strength is not obtained. Therefore, the rivet fastening device is inverted to make the member to be fastened 2 a receiving member to be fastened, or the member to be fastened 2 and the member to be fastened 3 are entirely inverted, and the member to be fastened 2 is similarly moved to the receiving side. As the members to be fastened, the members to be fastened 2 and 3 are fastened with sufficient strength. However, the reversing of the fastening device and the reversing of the member to be fastened require time, and the fastening operation cannot be performed quickly. In addition, the above reversal may not be possible depending on the restrictions on the shape of the member to be fastened, the limitations on the fastening site, and the like.
[0005]
International Publication No. WO 00/23213 discloses that a die is composed of a die body fixed to a fastening device body, and a center pin supported in the die body so as to be movable in the axial direction. A self-piercing rivet setting device is disclosed in which a concave portion is formed to guide a radially outward deformation of a leg tip of a rivet. In this fastening device, at the first time when the self-piercing rivet is driven into the member to be fastened, the center pin protrudes and is brought into contact with the member to be fastened in order to position the center of the leg of the self-piercing rivet. In the last step, the center pin is retracted into the die body. This conventional automatic piercing rivet fastening device is for positioning the center when the automatic piercing rivet is driven, and does not eliminate insufficient fastening due to an insufficient amount of undercut on the member to be fastened. .
[0006]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an automatic rivet fastening device that reduces or eliminates the restriction on the driving direction of a member to be fastened.
[0007]
[Means for Solving the Problems]
In order to achieve such an object, the present invention has a punch and a die for driving an automatic piercing rivet having a large-diameter head and a hollow leg hanging from the head into a plurality of members to be fastened, When the self-piercing rivet is driven into the member to be fastened, the leg is deformed so that the leg tip extends radially outward while penetrating the member to be fastened, and the leg tip is adjacent to the die. An automatic piercing rivet fastening device which is driven so as not to penetrate through a receiving-side fastened member but to stay therein, and interconnects the plurality of fastened members by the deformed expanding leg portion and the head; Wherein the die has a central pin extending toward the punch at a position for receiving the hollow portion of the leg of the automatic drilling rivet, and an outer peripheral side of the central pin, a tip of a leg tip of the automatic drilling rivet. Guide radially outward deformation The center pin and the die body are supported so as to be relatively movable along the axial direction of the center pin facing the punch, and are automatically pressed by the punch. When a piercing rivet is driven into the member to be fastened and the tip of the leg starts to penetrate the member to be fastened on the receiving side, the center pin contacts the die-side surface of the member to be fastened on the receiving side. And a means for moving the center pin relative to the die body.
[0008]
According to such an automatic piercing rivet fastening device, when the center pin of the die begins to pierce the receiving-side fastened member adjacent to the die with the tip of the leg of the automatic piercing rivet, the receiving-side fastened rivet is positioned on the die side. Since the center pin does not act on the receiving-side fastened member before that, the self-piercing rivet leg moves straight without expanding until it enters the receiving-side fastened member. When the part begins to penetrate the receiving-side fastened member, the center pin protrudes, and the tip of the rivet leg is largely expanded outward in the radial direction and started to expand. The cut amount is obtained. With this sufficient amount of undercut, even if the thickness of the receiving-side fastened member is less than half the thickness of the other fastened members (that is, the punch-side fastened member), it is sufficient. A binding force can be obtained. Therefore, it is possible to reduce or eliminate the restriction on the driving direction of the member to be fastened, and to reduce or eliminate the trouble of reversing the fastening device or reversing the member to be fastened as in the conventional fastening device. And quick fastening becomes possible. In addition, even in the conventional driving direction in which fastening is impossible, fastening can be performed, the restriction on the fastening portion is eliminated, and the application location or site of the automatic drilling rivet is expanded.
[0009]
In the above automatic piercing rivet, a C-shaped frame is provided, a punch is attached to one end of the C-shaped frame so as to be movable toward the other end, and a die is mounted on the other end of the C-shaped frame. A die body is mounted opposite the punch to receive the self-piercing rivet driven by the punch, and the die body is supported on the other end of the C-shaped frame so as to be movable in the axial direction of the central pin. Is fixed to the other end of the C-shaped frame so that the tip of the pin penetrates the die body and protrudes toward the punch. And a spring means for urging the die body to the punch side, which is provided between the die frame and the C-shaped frame.
[0010]
In that case, the movable die body is composed of a large-diameter cylindrical portion on the punch side and a small-diameter cylindrical portion that slides in the mounting hole at the other end of the C-shaped frame. Is formed as a hollow cylindrical body through which a center pin is slidably received, and the spring means is a disc spring provided between the large-diameter cylindrical portion and the C-shaped frame. The biasing force of the disc spring keeps the movable die body on the punch side until the tip of the leg of the automatic piercing rivet driven by the punch penetrates the member to be fastened and enters the member to be fastened on the receiving side. However, when a strong pressing force is applied to start the automatic piercing rivet leg portion through the receiving-side fastened member by the punch, the die body moves to the C-shaped frame side, and the center pin moves to the receiving-side fastened member. Spring force that allows it to abut the die-side surface of the .
[0011]
Further, at the other end of the C-shaped frame, a mounting hole for slidably receiving the small-diameter cylindrical portion of the die body is formed, and at the other end of the C-shaped frame, on the side opposite to the punch. A large diameter central pin receiving hole is formed following the mounting hole, and the die body is slidably mounted in the small diameter cylindrical part in the mounting hole, and a female screw is formed on the inner wall in the central pin receiving hole. The center pin can be attached to the center pin receiving hole by screwing into a female screw.
[0012]
In the automatic rivet having the C-shaped frame, the rivet includes a C-shaped frame, the die body is fixed to the other end of the C-shaped frame, a center pin is attached to the die body, and a tip of the pin is attached to the die body. A central pin storage chamber is formed to penetrate the die body and protrude toward the punch, and the central pin is movably supported in the central pin storage chamber along the axial direction of the pin. The means for moving the center pin relative to the die body may be hydraulic or pneumatic means for urging the center pin toward the punch by hydraulic or pneumatic pressure. In that case, the hydraulic or pneumatic means does not move the center pin until the leg end of the automatic piercing rivet driven by the punch penetrates the fastened member and enters the fastened member on the receiving side, When a strong pressing force is applied to start punching the self-piercing rivet leg into the receiving-side fastened member by the punch, the center pin is operated to abut the die-side surface of the receiving-side fastened member.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 schematically shows the entirety of the automatic rivet fastening device 9 according to one embodiment of the present invention. In FIG. 2, the automatic piercing rivet setting device 9 has a C-shaped frame 11 provided with a connecting portion 10 to an articulated robot arm (not shown). The C-shaped frame 11 is made of a rigid body in which an upper horizontal arm portion, a vertical arm portion to which the connecting portion 10 is attached, and a lower horizontal arm portion are integrated. At the end of the upper horizontal arm portion of the C-shaped frame 11, that is, at one end, a fastening mechanism 13 which is a main portion of the automatic rivet fastening device is attached. A punch 14 is movably attached to the end of the fastening mechanism 13 (the lower end in FIG. 2), and a receiver 15 is provided further from the punch 14 to the end. The automatic piercing rivet sent to the receiver unit 15 and held therein (see, for example, the automatic piercing rivet 1 in FIG. 1) is driven by the punch 14. Above the punch 14, a spindle driving unit 17 is provided, which pushes the punch 14 and drives an automatic piercing rivet held by a receiver unit below the punch 14. A die 18 is attached to the end of the lower horizontal arm of the C-shaped frame 11, that is, the other end of the C-shaped frame. The spindle drive unit 17 includes, for example, an electric motor 19 for driving, a reduction gear mechanism 21 and a gear mechanism 22 that transmit the torque of the motor, and a lead screw 23 that moves up and down while rotating by the torque from the motor, The rotation of the electric motor causes the lead screw to move downward, and this movement is transmitted to the punch 14 to strongly push the self-piercing rivet held by the receiver unit 15 toward the die 18. A plurality of members to be fastened (see, for example, members to be fastened 2 and 3 in FIG. 1) are placed on a die 18, and a plurality of members to be fastened are automatically pierced by lowering the punch 14. While being inserted, the members to be fastened are mutually fastened.
[0014]
The details of the die 18 according to the invention, mounted to receive the self-piercing rivet at the other end of the C-shaped frame 11, are shown in FIG. In FIG. 3, the die 18 has a central portion 25 extending toward the punch at a hollow portion of the leg of the self-piercing rivet, more specifically, at a position for receiving the axial center position of the rivet leg. A die body 27 having a recess 26 formed around the outer periphery to guide the tip of the leg of the self-piercing rivet to deform radially outward. The center pin 25 and the die body 27 are supported on the other end of the C-shaped frame 11 so as to be relatively movable along the axial direction of the center pin 25 facing the punch 14. In this embodiment, the die body 27 is supported by the C-shaped frame 11 so as to be movable in the axial direction of the center pin 25. The center pin 25 is fixed to the C-shaped frame 11 and penetrates the die body 27. The tip of the pin protrudes toward the punch 14. Therefore, the movable die body 27 is composed of a large-diameter cylindrical portion 30 on the punch side and a small-diameter cylindrical portion 33 that slides in a mounting hole 31 formed in the C-shaped frame 11. At the center of the portion, a hole 34 for slidably receiving the center pin 25 is formed as a hollow cylindrical body penetrating therethrough. The C-shaped frame 11 further has a large-diameter central pin receiving hole 35 formed below the mounting hole 31 of the die body 27, and the central pin receiving hole 35 has an internal thread formed on an inner wall. The central pin 25 is formed with a large-diameter cylindrical mounting portion 38, and a male screw that fits the female screw of the central pin receiving hole 35 is formed on the outer peripheral surface thereof. Thus, the center pin 25 can be fixed to the C-shaped frame 11 by screwing the mounting portion 38 of the center pin 25 into the center pin receiving hole 35. A set screw 39 is attached to the C-shaped frame 11 so that the fixing of the center pin 25 is not loosened.
[0015]
In the present invention, the self-piercing rivet pressed by the punch 14 is driven into the member to be fastened, and its leg end starts to penetrate the member to be fastened on the receiving side (see the member to be fastened 3 in FIG. 1). At this time, means is provided for moving the center pin 25 relative to the die body 27 so that the center pin 25 contacts the die-side surface of the receiving-side fastened member. In the embodiment shown in FIG. 3, the spring means is provided between the die body 27 and the C-shaped frame 11 and biases the die body 27 toward the punch 14. More specifically, the spring means includes a disc spring 41 provided between the large-diameter cylindrical portion 30 and the C-shaped frame 11. The disc spring 41 is mounted on the seat 40 placed on the C-shaped frame 11 to prevent the C-shaped frame from being worn when the disc spring 41 is bent. The urging force of the disc spring 41, that is, the force of pushing up the large-diameter cylindrical portion 30 to the punch side, is such that the tip of the leg of the automatic piercing rivet driven by the punch penetrates the member to be fastened to the member to be fastened on the receiving side. The movable die body is urged toward the punch side until it enters, but when a strong pressing force is applied by the punch which starts to penetrate the self-piercing rivet leg into the receiving-side fastened member, the die body 27 is moved to the C-shaped frame 11. The spring force is set to allow the center pin 25 to contact the die-side surface of the receiving-side fastened member. At the lower end of the small-diameter cylindrical portion 33, a C ring 42 for stopping is provided to prevent the die body 27 from coming out of the mounting hole 31 by the urging force of the disc spring.
[0016]
An operation of driving the automatic piercing rivet using the automatic piercing rivet fastening device 9 will be described with reference to FIGS. In FIG. 4, the automatic piercing rivet 1 is automatically fed from a feeding unit (not shown) to the receiver unit 15 and is held in the receiver unit 15 below the punch 14. The punch 14 receives the pushing force from the spindle drive unit 17 (FIG. 2), and moves downward to drive the automatic piercing rivet 1 into the workpiece 2 on the punch side. By this driving, the hollow leg 5 of the automatic drilling rivet 1 penetrates the member to be fastened 2 and advances. As shown in FIG. 4, in the present invention, in the first stage of the driving, the die body 27 of the die 18 is in a raised state, and the center pin 25 is attached to the receiving member 3 on the receiving side adjacent to the die 18. Does not abut, the piercing rivet leg 5 moves straight without expanding in the workpiece 2. Thereafter, the piercing of the rivet leg 5 of the automatic piercing proceeds to reach the receiving member 3 on the receiving side adjacent to the die, and the pressing force on the rivet from the punch 14 applies the rivet leg 5 to the receiving member 3 on the receiving side. When the force is strong enough to penetrate, the disc spring 41 bends and the die body 27 descends toward the C-shaped frame 11. This is shown in FIG.
[0017]
In FIG. 5, when the tip of the leg 5 of the automatic drilling rivet 1 starts to penetrate the receiving member 3 on the receiving side adjacent to the die 18, the tip of the center pin 25 faces the die-side surface of the receiving member 3. Comes into contact with The center pin 25 acts to push up the portion of the receiving-side fastened member 3 at the abutting position against the pressing force of the receiving-side fastened member receiving the pressing force of the punch 14, and the position is set to the rivet leg portion. 5, the tip of the rivet leg 5 of the automatic piercing rivet 1 is largely expanded outward in the radial direction and starts to expand. As a result, the leg 5 is deformed so as to largely expand outward in the radial direction, penetrates through the receiving-side fastened member, and the driving is completed shortly before penetrating the receiving-side fastened member. 5 has a large amount of deformation in the radial direction, and a sufficient penetration length of the leg portion 5 in the radial direction, that is, an undercut amount can be obtained. The two members to be fastened 2 and 3 are fastened to each other by the deformed expanding leg 5 and the large-diameter head 4 of the rivet 1. In the present invention, the thickness of the receiving-side fastened member 3 is set to be equal to the thickness of the other fastened members 2 (that is, the punch-side fastened member) by a sufficient amount of undercut of the expanded leg portion 5. Even if the members to be fastened are not more than / 2, the members to be fastened 2 and 3 can be fastened to each other with a sufficient bonding force. Thereby, it is possible to reduce or eliminate the restriction on the driving direction of the member to be fastened, and to reduce the labor of inverting the fastening device or inverting the member to be fastened as in the conventional automatic piercing rivet fastening device. , Or can be omitted, enabling quick fastening. In addition, even in the conventional driving direction in which fastening is impossible, fastening can be performed, the restriction on the fastening portion is eliminated, and the application location or site of the automatic drilling rivet is expanded.
[0018]
FIG. 6 shows another embodiment of the automatic piercing rivet fastening device according to the present invention. In this embodiment, a die 43 is fixed to a C-shaped frame 11 so as to be opposed to a punch 14 by a die body 45. And a central pin 46 movably held in the die body 45. For this reason, a central pin housing chamber 47 is formed in the die body 45 to house the center pin 46 such that the tip of the pin penetrates the die body and protrudes toward the punch 14. The center pin 46 is movably supported in the center pin housing chamber 47 along the axial direction of the pin. Therefore, in this embodiment, the center pin 46 moves toward the punch 14. The means for the movement is hydraulic or pneumatic means for supplying hydraulic or pneumatic pressure from a lower portion of the central pin housing chamber 47 to urge the central pin 46 toward the punch side. This hydraulic or pneumatic means keeps the central pin in place until the leg tip 5 of the automatic piercing rivet driven by the punch 14 penetrates the workpiece 2 on the punch side and enters the workpiece 3 on the receiving side. 46 is not moved, but if a strong pressing force is applied by the punch 14 to start the automatic piercing rivet leg 5 through the receiving-side fastened member 3, the center pin 46 contacts the die-side surface of the receiving-side fastened member 3. Operate to make contact. When the die 43 of FIG. 6 is used, similarly to the case described with reference to FIGS. 4 and 5, when the rivet 1 is driven into the workpieces 2 and 3, the legs 5 of the rivet 1 are sufficiently A small amount of undercut penetrates the receiving member 3.
[0019]
【The invention's effect】
According to the present invention, the center pin of the die does not act on the receiving-side fastened member until the tip end of the leg of the automatic piercing rivet starts to penetrate the receiving-side fastened member adjacent to the die. When the tip begins to penetrate the receiving member, the center pin acts reliably, and the rivet leg that has been straight forward without expanding until it enters the receiving member is attached to the receiving member. When the penetrating operation starts, the center pin acts to greatly expand the tip of the rivet leg outward in the radial direction and start to expand, so that a sufficient amount of undercut is obtained. With this sufficient amount of undercut, even if the thickness of the receiving-side fastened member is less than half the thickness of the other fastened members (that is, the punch-side fastened member), it is sufficient. The coupling force can be obtained, the restriction on the driving direction of the member to be fastened can be reduced or eliminated, and the time required for reversing the fastening device or reversing the member to be fastened as in the conventional fastening device can be reduced. It can be reduced or omitted, allowing for quicker fastening. Further, the fastening can be performed even in the conventional driving direction in which the fastening is impossible, the limitation of the fastening portion is eliminated, and the application places and the portions of the automatic rivet are expanded.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a state of fastening of a member to be fastened in which a self-piercing rivet is driven by a conventional fastening device.
FIG. 2 is a schematic front view of the automatic rivet fastening device according to one embodiment of the present invention.
FIG. 3 is a sectional view of a die portion of the automatic rivet fastening device according to one embodiment of the present invention.
FIG. 4 is a cross-sectional view of a die and a punch portion showing a state in which an automatic piercing rivet is being driven into a member to be fastened using the automatic piercing rivet fastening device shown in FIGS. 2 and 3;
FIG. 5 is a cross-sectional view similar to FIG. 4, showing a state in which an automatic piercing rivet is driven into a member to be fastened using the fastening device according to the present invention and the members to be fastened are connected to each other.
FIG. 6 is a sectional view of a die portion of an automatic rivet fastening device according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Automatic piercing rivet 2 Punch side fastening member 3 Receiving side fastening member 4 Large diameter head of automatic piercing rivet 5 Leg of automatic piercing rivet 6 Undercut amount 9 Automatic piercing rivet fastening device 10 Connecting part to robot arm Reference Signs List 11 C-type frame 13 Fastening mechanism part 14 Punch 15 Receiver part 17 Spindle drive part 18 Die 19 Motor 21 Reduction gear mechanism 22 Gear mechanism 23 Lead screw 25 Central pin 26 Guide recess 27 Die body 30 Large diameter cylindrical part 31 Hole 33 Small-diameter cylindrical portion 35 Center pin accommodation hole 37 Female screw 38 Center pin mounting portion 39 Set screw 41 Disc spring 42 C ring 43 Die 45 Die body 46 Center pin 47 Center pin storage chamber 49 Pump

Claims

A punch and a die for driving an automatic piercing rivet having a large-diameter head and a hollow leg hanging down from the head into a plurality of workpieces, and driving the automatic piercing rivet into the workpiece. The leg is deformed so that the tip of the leg extends radially outward while the leg penetrates the member to be fastened, and the tip of the leg does not penetrate the member to be fastened on the receiving side adjacent to the die. In the automatic piercing rivet fastening device, which is driven so as to remain therein, and interconnects the plurality of members to be fastened by the deformed expanding legs and the head.
The die has a central pin extending toward the punch at a position for receiving the hollow portion of the leg of the self-piercing rivet, and a radially outer side of the tip of the leg of the self-piercing rivet on an outer peripheral side of the central pin. The central pin and the die body are supported so as to be relatively movable along the axial direction of the central pin facing the punch, When the self-piercing rivet pressed by the punch is driven into the member to be fastened and the tip of the leg thereof starts to penetrate the member to be fastened on the receiving side, the center pin is moved toward the die side of the member to be fastened on the receiving side. An automatic rivet fastening device comprising means for moving the center pin relative to the die body so as to abut against a surface.

The apparatus according to claim 1, further comprising a C-shaped frame, wherein the punch is movably mounted on one end of the C-shaped frame toward the other end of the C-shaped frame, and wherein the die includes the C-shaped frame. At the other end of the frame, the die body is attached to the other end of the C-shaped frame in the axial direction of the center pin so as to receive the self-piercing rivet driven by the punch. The center pin is movably supported, and the center pin is fixed to the other end of the C-shaped frame so as to penetrate the die body so that the tip of the pin projects toward the punch. The device for moving the die body relative to the die body is spring means provided between the die body and the C-shaped frame to bias the die body toward the punch.

3. The apparatus according to claim 2, wherein the movable die body includes a large-diameter cylindrical portion on the punch side and a small-diameter cylindrical portion that slides in a mounting hole at the other end of the C-shaped frame. The center of both cylindrical portions is formed as a hollow cylindrical body through which a hole for slidably receiving the central pin is penetrated, and the spring means includes the large-diameter cylindrical portion and the C The disc spring is provided between the mold frames. The biasing force of the disc spring is such that the tip of the leg of the automatic piercing rivet driven by the punch penetrates the member to be fastened and the member to be fastened on the receiving side. By the time the movable die body is urged toward the punch side, a strong pressing force that starts to penetrate the self-piercing rivet leg portion into the receiving-side fastened member is applied by the punch. Move to C-type frame side And wherein the center pin is spring force that allows the contact to the surface of the die side of the receiving-side workpieces.

4. The device according to claim 3, wherein the other end of the C-shaped frame is provided with a mounting hole for slidably receiving the small-diameter cylindrical portion of the die body, and the other end of the C-shaped frame. In addition, a large-diameter central pin receiving hole following the mounting hole is formed on the side opposite to the punch, and the die body is slidably mounted on the small-diameter cylindrical portion in the mounting hole. The center pin receiving hole is formed with an internal thread on an inner wall, and the central pin is attached to the central pin receiving hole by screwing to the internal thread.

The apparatus according to claim 1, further comprising a C-shaped frame, wherein the punch is movably attached to one end of the C-shaped frame toward the other end of the C-shaped frame, and wherein the die includes the C-shaped frame. At the other end of the frame, mounted opposite the punch to receive an automatic piercing rivet driven by the punch, the die body is fixed to the other end of the C-shaped frame, A central pin accommodation chamber is formed for accommodating the center pin so that the tip of the pin penetrates the die body and protrudes toward the punch, and the center pin is provided in the center pin accommodation chamber. The means for movably supporting the center pin relative to the die body is supported movably along the axial direction, and the means for pressing the center pin toward the punch by hydraulic or pneumatic means is hydraulic or pneumatic means. Being Device according to claim.

6. The apparatus according to claim 5, wherein the hydraulic or pneumatic means is configured such that a leg end of an automatic piercing rivet driven by the punch penetrates the member to be fastened and enters the member to be fastened on the receiving side. Until the central pin is not moved, but if a strong pressing force is applied by the punch to start the automatic piercing rivet leg to penetrate the receiving-side fastened member, the central pin is moved to the die of the receiving-side fastened member. An apparatus operable to abut against a side surface.